In many audio display situations it is desirable to compare the performance of a plurality of high fidelity speakers under listening conditions that are essentially the same. Compensation may be required to adjust for changes in listening volume when comparing speakers of differing efficiency. Comparison devices presently available are of limited utility in that some have no provision for listening volume compensation. Other devices use active amplifier stages which are complex, expensive and may introduce distortion into the amplification stages of the audio system provided to drive the speakers. Other devices compensation means may electrically affect the interface between amplifier and speaker and thus cause a change of sound quality from the speaker as listening volume is adjusted by the device.